Featured Research

from universities, journals, and other organizations

'Wrong'-time eating reduces fertility in fruit flies: Study points to fertility-metabolism connection

Date:
June 8, 2011
Source:
University of Pennsylvania School of Medicine
Summary:
Researchers manipulated circadian rhythms in fruit flies and measured the affect on egg-laying capacity. But they stress what's true in flies grown in a lab does not necessarily hold for humans, and any potential link between diet and reproduction would have to be independently tested. "I would say that eating at the wrong time of the day has deleterious consequences for physiology," says lead author Amita Sehgal.

Dieticians will tell you it isn't healthy to eat late at night: it's a recipe for weight gain. In fruit flies, at least, there's another consequence: reduced fertility.

That's the conclusion of a new study in Cell Metabolism by researchers at the Perelman School of Medicine at the University of Pennsylvania, in which they manipulated circadian rhythms in fruit flies and measured the affect on egg-laying capacity.

Lead author Amita Sehgal, PhD, John Herr Musser Professor of Neuroscience, stresses, though, that what is true in flies grown in a lab does not necessarily hold for humans, and any potential link between diet and reproduction would have to be independently tested.

"I wouldn't say eating at the wrong time of the day makes people less fertile, though that is the implication," says Sehgal, who is also a Howard Hughes Medical Institute Investigator. "I would say that eating at the wrong time of the day has deleterious consequences for physiology."

It's All Connected

Many aspects of animal biology cycle over the course of a day. Sleep and wakefulness, activity and rest, body temperature, and more, all fluctuate in a pattern called a circadian rhythm. Disruption of these rhythms has been shown to negatively affect physiology. Shift workers, for instance, often suffer from psychological and metabolic issues that colleagues on normal hours do not. Rodents with disrupted circadian rhythms are more likely to develop obesity.

For a while, Sehgal explains, researchers believed animals had a single master molecular clock, located in the brain, that controlled activity throughout the body. In recent years, however, they have come to understand that some individual organs also have their own, independent clocks, like townspeople who wear a wristwatch and keep it synchronized with the clock in city hall.

The mammalian liver is one organ that has its own independent clock. In 2008, Sehgal's team discovered that the fruit fly equivalent of the liver, called the fat body, has its own clock, which controls eating and food storage. They wanted to know what would happen if the fat body clock became desynchronized from the master clock in the brain.

Decoupling Clocks

First, her team asked which fly genes are controlled specifically by the fat body clock. Using gene chip microarrays, they identified 81 genes related to lipid and carbohydrate metabolism, the immune system, and reproduction that fit those criteria.

Next, the researchers attempted to decouple the fat body and central clocks by keeping the flies in constant darkness (to eliminate effects of light on these clocks) and feeding them at times when they don't normally eat. They found the two clocks could be desynchronized: disrupting the animals' feeding cycles altered the cycling of genes controlled by the fat-body clock, but not those regulated by the central clock itself itself.

Finally, the team addressed the functional consequences of this desynchronization, by counting the number of eggs the flies laid under different conditions. Flies fed at the "right" time of the day deposited about 8 eggs per day, compared to about 5 when they fed at the "wrong" time.

"Circadian desynchrony caused by feeding at the 'wrong' time of day leads to a defect in overall reproductive capacity," the authors wrote.

The next question to pursue, Sehgal says, is finding the molecular mechanism that controls this phenomenon: How does the fat body communicate with the ovaries. And, more importantly, is this effect restricted to fruit flies, or does it also occur in higher organisms, including humans.

The research was funded by the Howard Hughes Medical Institute and the National Institute of Neurological Disorders and Stroke and the National Heart, Lung, and Blood Institute.

Other authors include Penn postdoctoral fellows Kanyan Xu, Justin R. DiAngelo, and Michael E. Hughes, as well as John B. Hogenesch, associate professor of Pharmacology.


Story Source:

The above story is based on materials provided by University of Pennsylvania School of Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kanyan Xu, Justin R. DiAngelo, Michael E. Hughes, John B. Hogenesch, Amita Sehgal. The Circadian Clock Interacts with Metabolic Physiology to Influence Reproductive Fitness. Cell Metabolism, 2011; 13 (6): 639-654 DOI: 10.1016/j.cmet.2011.05.001

Cite This Page:

University of Pennsylvania School of Medicine. "'Wrong'-time eating reduces fertility in fruit flies: Study points to fertility-metabolism connection." ScienceDaily. ScienceDaily, 8 June 2011. <www.sciencedaily.com/releases/2011/06/110607171832.htm>.
University of Pennsylvania School of Medicine. (2011, June 8). 'Wrong'-time eating reduces fertility in fruit flies: Study points to fertility-metabolism connection. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2011/06/110607171832.htm
University of Pennsylvania School of Medicine. "'Wrong'-time eating reduces fertility in fruit flies: Study points to fertility-metabolism connection." ScienceDaily. www.sciencedaily.com/releases/2011/06/110607171832.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins